In one type of automated welding machine, a spool of welding or filler wire is operatively joined to a welding torch for providing thereto filler material used in welding of a metallic part. The torch is also operatively joined to a gas supply which provides a shielding gas for protecting the molten welding pool formed during the welding operation. Although the torch may be manually held, it is commonly supported in a carriage so that it may be automatically moved during operation, or held stationary with the part being moved past the torch, and automatically controlled by a dedicated controller of the welding machine. A typical welding machine controller may include a digital programmable microprocessor or other control system operatively joined to the various components of the welding machine for controlling the entire operation thereof including start-up.
A typical welding wire spool contains a substantial length of welding wire wound thereon which is typically used in the production of a specific part that requires a specific welding process and a specific compatible welding material. For parts requiring a different welding material and diameter of filler wire for a specified welding process, or when the spool is empty and requires replacement, the wire spool on the welding machine must be correspondingly changed to the correct spool. The wire spool is manually changed by the operator of the welding machine who must ensure that the correct wire spool is mounted in the welding machine for the specified parts to be welded. The various wire spools contain legible labels thereon identifying the welding wire and its diameter. However if an incorrect wire spool is mounted in the welding machine due to inadvertently misreading the spool label, the resulting welding operation on the parts will, of course, be inappropriate which will require suitable, and expensive, remedial action.